Steve jahn Posted August 31, 2007 Share Posted August 31, 2007 I was looking at the Detail and scale book on the F-8 Crusader.There are a couple of pictures of the piston that lifts the wing.I was wondering about this set up.This piston is the only thing that holds the front of the wing on to the aircraft.It seems that since it is only on the right side the wing would twist some what when g's were aplied to the aircraft.This little piston just does not seem strong enough.Was there some sort of lock down that I am not seeing. Link to post Share on other sites
Tailspin Turtle Posted August 31, 2007 Share Posted August 31, 2007 The wing's center of pressure was aft of the wing hinge, so the wing was actually holding itself in place. The more G's you pull, the more down force on the front stops. (I'm not sure what happened in inverted flight, but it wasn't a problem.) There reportedly was a lock on the actuator, but my guess is that it was more to remind the pilot not to raise the wing at too high a speed. It may, however, have been there for the negative g condition. There is a report on the web by a NACA pilot claiming that the wing gapped under load with the original design, which isn't consistent with the above, unless it was some sort of rolling maneuver. There were wing attach failures, but none were attributed to the actuator - the initiation was a gross overload of the wing pivot point. Link to post Share on other sites
Ishthe47guy Posted August 31, 2007 Share Posted August 31, 2007 As big as a F-8 geek as I am, I always wondered the exact same thing as Steve, but it never crossed my mind to post it. Tailspin, I've had a few classes in aerodynamics myself, & you answer had me head right to my bench where I've go a Mono F-8 laying there gathering dust. I put the wings on the fuselage & the light bulb lit on how the center of pressure could be aft of the wing hinges. Its all about the sweep. An enlightened Chris Ish Link to post Share on other sites
Steve jahn Posted September 1, 2007 Author Share Posted September 1, 2007 Well finally some one answered it.Thanks for that insight.That makes perfect sense.I have wondered about that for years.I went to my Hasegawa F-8(still in the box) and taped the pieces together and there it is. Link to post Share on other sites
Almansur Posted September 1, 2007 Share Posted September 1, 2007 Yes... and no. There were at least a couple of accidents where the wing separated in flight. Remember one case where the pilot hot-dogged on the break with the wing raised... the wing failed and separated. Think 150 or so Gs on that fuselage whiplash and you can picture what happened to the pilot in a nanosecond... Link to post Share on other sites
Tailspin Turtle Posted September 1, 2007 Share Posted September 1, 2007 Yes... and no. There were at least a couple of accidents where the wing separated in flight. Remember one case where the pilot hot-dogged on the break with the wing raised... the wing failed and separated. Think 150 or so Gs on that fuselage whiplash and you can picture what happened to the pilot in a nanosecond... According to Crusader! by Paul Gillcrist, a Navy pilot overstressed the Crusader wing attachment on 8 April 1963 at Cecil Field, Florida in the break for landing, "easily in excess of 600 knots." The wing was definitely not up (it was supposed to be down above 220 KIAS) but that may be the incident you remember. There was a prior accident in 1961 with the wing coming off, again at high speed with the wing lowered. The pilot ejected successfully. I don't have the copy of the accident report but the pilot involved sent me an email "It was determined that it is impossible to "pull' the wing off unless you break the aft hinge, which is a very heavy fitting and the G required would not be available, or the pilot would black out long before it was reached." In his accident, the wing folding lock had failed and the sequence was 1) wing fold outer panel failure, 2) aft hinge of the wing incidence failed as a result of the rolling moment caused by the asymmetrical lift situation, 3) actuator rod and cylinder failed under tension after the (wing incidence) hinge broke. There were a least three earlier inflight breakups, all due to different causes at high speeds, none due to wing incidence actuator failure. Link to post Share on other sites
Phantomologist Posted September 2, 2007 Share Posted September 2, 2007 The NATOPS shows the wing up at 220kts in the approach drawings, down above that. I was told the g limit, wing up, is 2g, but don't have the suppliment to the NATOPS to be sure. bill Link to post Share on other sites
Phantomologist Posted September 2, 2007 Share Posted September 2, 2007 Just for grins, here is a photo of the actuator on RF-8G 146882 at the Frontiers of Flight Museum in Dallas. Link to post Share on other sites
Slartibartfast Posted September 3, 2007 Share Posted September 3, 2007 Oh boy, there's the perfect location for Revell to mold in their classic format. Everything else needs to be handled by Tamigawa. Link to post Share on other sites
Steve jahn Posted September 3, 2007 Author Share Posted September 3, 2007 (edited) Wow,look how small that is.I know of coarse it worked(99 % of the time),but that had to give the pilot some time for pause.How many times was it said,"how does that hold the wing on"? Edited September 3, 2007 by Steve jahn Link to post Share on other sites
Ishthe47guy Posted September 3, 2007 Share Posted September 3, 2007 Wow,look how small that is.I know of coarse it worked(99 % of the time),but that had to give the pilot some time for pause.How many times was it said,"how does that hold the wing on"? Ditto, man. Ditto. Leave it to you Bill to be able to get such a close up picture in a timely manner. Glad you are around. Might finally get to meet you at the Warbird Roundup this year. Chris Ish Link to post Share on other sites
Phantomologist Posted September 3, 2007 Share Posted September 3, 2007 Ditto, man. Ditto.Leave it to you Bill to be able to get such a close up picture in a timely manner. Glad you are around. Might finally get to meet you at the Warbird Roundup this year. Chris Ish Chris, I hope to meet you as well. We have been working our tails off to get the fleet ready for the show. Have you seen the A-4C? The AF OV-10 just got painted and looks great. Scooby is next. She is going back to triptrey markings on the right side, a scheme that will be fairly accurate for the buno, the other side will stay VX-30 for another year or so, but will be refreshed. It is looking like we are going to get our own RF-8G to play with! ;) bill Link to post Share on other sites
Aggressor Supporter Posted September 5, 2007 Share Posted September 5, 2007 That is a nice reference pic Bill. Never seen that up close before. Link to post Share on other sites
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